Get audio sample value

Question

How can print and modify audio sample value in C#?

byte[] array = File.ReadAllBytes("C:\\audioclip.wav");

for (int i = 44; i < array.Length - 1; i++)
{
    Console.WriteLine(" byte " + i + "  value  " + array[i]);
    System.Threading.Thread.Sleep(100);
}

Is it right?

What are you trying to accomplish? why does your loop start at 44? — Jonas Praem, Jan 26 '19 at 18:03
I try to perform Audio Steganography (hide text in audio sample),and my loop start at 44 because the (wav) audio file actual data (sample) start in it (44). — Yas, Jan 26 '19 at 18:14
You dont need minus 1 in your for condition. `i < array.Length`- is the end of the file. (since you do lower than). - I don't understand what exactly is the issue? — Jonas Praem, Jan 26 '19 at 18:21

Jim W · Accepted Answer · 2019-01-28T01:35:19.567

0

.wav files may be compressed, if so the sample values won't be stored as simple bytes. You would need to use a library (as mentioned in the comments).

If your file is uncompressed then you are almost correct. Uncompressed .wav files contain 16bit samples, not 8bit. So ReadAllBytes isn't very helpful.

Instead use a BinaryReader and reader.ReadInt16() to read each sample, eg.

List<Int16> sampleBuffer = new List<Int16>();
using(var inputStream = File.Open(inputFile)){
 using (var reader = new BinaryReader(inputStream))      
 {           
     while (inputStream.Position < inputStream.Length)
         sampleBuffer.Add(reader.ReadInt16());      
 }
}

edited Jan 28 '19 at 01:35

answered Jan 26 '19 at 21:30

Jim W

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Thank you, but why when I print the result of list (sampleBuffer) value there is a negative number in the beginning of results. – Yas Jan 27 '19 at 13:46
@Yas I believe that is correct, see https://stackoverflow.com/questions/5890499/pcm-audio-amplitude-values – Jim W Jan 28 '19 at 01:38

Get audio sample value

1 Answers1